(a) Field of the Invention
The present invention relates to a device for measuring and controlling the rate of flow of a fluid.
(b) Description of the Prior Art
Heretofore, devices of this type for measuring and controlling the rate of microflow have employed needle valves and slits and required high machining accuracy. Another problem is that the coefficients of discharge tend to vary with the area of opening. Thus, it has been difficult to obtain a device which provides high accuracy for measurement.